US 7869851 B2 Abstract A method of computing an insulin bolus quantity when a measured glucose value in a current time interval exceeds a target glucose value for the current time interval and when a time duration of glucose lowering action of the bolus to be administered spans the current and a number of the next adjacent time intervals, may comprise determining a corresponding number of percentages of insulin action of the recommended bolus quantity that will each be used lowering the glucose level during a respective one of the number of time intervals, and computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for a last one of the number of next adjacent time intervals, the insulin sensitivities for the current and each of the number of next adjacent time intervals, and the corresponding number of percentages.
Claims(26) 1. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current time interval of a number of adjacent time intervals, each of the number of adjacent time intervals defining an associated target glucose value and an insulin sensitivity value, exceeds the target glucose value for the current time interval and when a time duration of glucose lowering action of the recommended insulin bolus quantity to be administered extends from the current time interval into a number of next adjacent time intervals, the method comprising the steps of:
determining with a processor a plurality of percentages each corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during a respective one of the current time interval and each of the number of next adjacent time intervals, and
computing with the processor the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for a last one of the number of next adjacent time intervals, the insulin sensitivities for the current and each of the number of next adjacent time intervals, and the plurality of percentages.
2. The method of
and wherein the step of determining with a processor a plurality of percentages includes:
determining with the processor a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval,
determining with the processor a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next adjacent time interval,
and wherein the computing step includes computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages.
3. The method of
4. The method of
and wherein the step of determining a first percentage includes determining the first percentage as a function of the current interval bolus activity time and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity.
5. The method of
6. The method of
7. The method of
8. The method of
and wherein the step of determining a second percentage includes determining the second percentage as a function of the next interval bolus activity time and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity.
9. The method of
10. The method of
11. The method of
12. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current time interval of a number of adjacent time intervals, each of the number of adjacent time intervals defining an associated target glucose value and an insulin sensitivity value, exceeds the target glucose value for the current time interval, the method comprising:
determining with a processor whether a time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity extends from the current time interval into at least a next adjacent time interval, and
computing with the processor the recommended bolus quantity as a function of the measured glucose value, the target glucose value for the current time interval and the insulin sensitivity value for the current time interval only if the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity is confined to the current time interval.
13. The method of
determining with the processor a plurality of percentages each corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during a respective one of the current time interval and each of the number of next adjacent time intervals, and
computing with the processor the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for a last one of the number of next adjacent time intervals, the insulin sensitivities for the current and each of the number of next adjacent time intervals, and the plurality of percentages.
14. The method of
and wherein the step of determining a plurality of percentages includes:
determining with the processor a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval,
determining with the processor a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next adjacent time interval,
and wherein the computing step includes computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages.
15. The method of
16. The method of
17. The method of
18. The method of
19. The method of
20. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current time interval of a number of adjacent time intervals, each of the number of adjacent time intervals defining an associated target glucose value and an insulin sensitivity value, exceeds the target glucose value for the current time interval and when a time duration of glucose lowering action of the recommended insulin bolus quantity to be administered extends from the current time interval into the next adjacent time interval, the method comprising:
determining with a processor a first difference as a difference between the target glucose value for the current time interval and the target glucose value for the next adjacent time interval,
determining with the processor a second difference as a difference between the insulin sensitivity value for the current time interval and the insulin sensitivity value for the next adjacent time interval, and
computing with the processor the recommended bolus quantity as a function of the measured glucose value, the target glucose value for the current time interval and the insulin sensitivity value for the current time interval only if the first difference is less than or equal to a first threshold value and the second difference is less than or equal to a second threshold value.
21. The method of
determining with the processor a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval,
determining with the processor a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next adjacent time interval, and
computing with the processor the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages.
22. The method of
23. The method of
24. The method of
25. The method of
26. The method of
Description The present invention relates generally to techniques for managing glucose levels in diabetic individuals, and more specifically to systems for determining and recommending insulin administration as a way of managing glucose levels. A number of handheld and other systems for managing diabetes care currently exist. Many such systems provide for the partitioning of an extended time period, e.g., one or more days, into a number of adjacent time intervals. Within each time interval, a specific glucose target and a specific insulin sensitivity value, e.g., in units of mg/dl per international unit (IU) of insulin, may be established. It is desirable with such systems to provide for accurate determination and recommendation of additive correction insulin bolusing, regardless of when such bolusing may occur relative to adjacent time intervals, to thereby closely track and satisfy the user's insulin needs. The present invention may comprise one or more of the features recited in the attached claims, and/or one or more of the following features and combinations thereof. A diabetes care system may have a number of adjacent time intervals each defining an associated target glucose value and an insulin sensitivity value. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current time interval exceeds the target glucose value for the current time interval and when a time duration of glucose lowering action of the recommended insulin bolus quantity to be administered spans the current time interval and a next adjacent time interval, may comprise determining a corresponding number of percentages each corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during a respective one of the number of time intervals between the current time interval and the number of next adjacent time intervals. The recommended bolus quantity may be computed as a function of the measured glucose value, the target blood glucose level for a last one of the number of next adjacent time intervals, the insulin sensitivities for the current and each of the number of next adjacent time intervals, and the corresponding number of percentages. The number of next adjacent time intervals may be one, and the step of determining a corresponding number of percentages may include determining a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval, and determining a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next time interval. The computing may then comprise computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages. The step of determining a first percentage may include determining the first percentage as a function of at least a current time in the current time interval at which the measured bolus value was measured, a beginning time of the next adjacent time interval and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity. The method may further include the step of computing a current interval bolus activity time as a difference between the beginning time of the next adjacent time interval and the current time. The step of determining a first percentage may then include determining the first percentage as a function of the current interval bolus activity time and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity. The step of determining a first percentage may include extracting the first percentage value from a table populated with first percentage values as functions of current interval bolus activity time values and time duration values of glucose lowering action of the subsequently administered recommended insulin bolus quantity. The step of determining a second percentage may include computing the second percentage as a difference between one hundred percent and the first percentage. Alternatively, the step of determining a second percentage may include determining the second percentage as a function of at least a current time in the current time interval at which the measured bolus value was measured, a beginning time of the next adjacent time interval and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity. In this embodiment, the method may further include the step of computing a next interval bolus activity time as a difference between the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity and a current interval bolus activity time corresponding to a difference between the beginning time of the next adjacent time interval and the current time. The step of determining a second percentage may then include determining the second percentage as a function of the next interval bolus activity time and the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity. The step of determining a second percentage may include extracting the second percentage value from a table populated with second percentage values as functions of next interval bolus activity time values and time duration values of glucose lowering action of the subsequently administered recommended insulin bolus quantity. The step of determining a first percentage may include computing the first percentage as a difference between one hundred percent and the second percentage. In either case, the method may further including the step of executing both determining steps and the computing step only if the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity extends into the next adjacent time interval by a predefined time amount. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current one of the time intervals exceeds the target glucose value for the current time interval, may comprise determining whether a time duration of glucose lowering action of the recommended insulin bolus quantity to be administered spans the current time interval and at least the next adjacent time interval. The method may further include computing the recommended bolus quantity as a function of the measured glucose value, the target glucose value for the current time interval and the insulin sensitivity value for the current time interval only if the time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity is confined to the current time interval. The method may further include a number of additional steps if the time duration of the glucose lowering action of the subsequently administered recommended insulin bolus quantity otherwise spans the current and at least the next adjacent time interval. For example, the method may include determining a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval. The method may further include determining a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next time interval. The method may further include computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages. A method of computing a recommended insulin bolus quantity when a measured glucose value in a current one of the time intervals exceeds the target glucose value for the current time interval and when a time duration of glucose lowering action of the subsequently administered recommended insulin bolus quantity spans the current time interval and a next adjacent time interval, may comprise determining a first difference as a difference between the target glucose value for the current time interval and the target glucose value for the next adjacent time interval. The method may further include determining a second difference as a difference between the insulin sensitivity value for the current time interval and the insulin sensitivity value for the next adjacent time interval. The method may further include computing the recommended bolus quantity as a function of the measured glucose value, the target glucose value for the current time interval and the insulin sensitivity value for the current time interval only if the first difference is less than a first threshold value and the second difference is less than a second threshold value. The method may further including a number of additional steps if either of the first difference exceeds the first threshold value and the second difference exceeds the second threshold value. For example, the method may include determining a first percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the current time interval. The method may further include determining a second percentage corresponding to a percentage of insulin action of the recommended bolus quantity that will be used lowering the glucose level during the next time interval. The method may further include computing the recommended bolus quantity as a function of the measured glucose value, the target blood glucose level for the next adjacent time interval, the insulin sensitivities for the current and next adjacent time intervals, and the first and second percentages. These and other features of the present invention will become more apparent from the following description of the illustrative embodiments. For the purposes of promoting an understanding of the principles of the invention, reference will now be made to a number of illustrative embodiments shown in the attached drawings and specific language will be used to describe the same. Referring now to The insulin bolus recommendation system The insulin bolus recommendation system In another illustrative embodiment, the insulin bolus recommendation system As another example of the embodiment of the insulin bolus recommendation system In this particular embodiment, the insulin bolus recommendation software algorithms thus reside in the remote computer or web server It will be appreciated that the insulin bolus recommendation system As described hereinabove, the insulin bolus recommendation system Referring now to The user of the system where BGM is the blood glucose level measured at the current time, T Referring again to As illustrated in the example just given, the conventional correction bolus equation works well as long as the correction bolus is administered sufficiently early in the current time interval so that the duration of the glucose lowering action of the administered insulin bolus, T One effective technique for improving the accuracy of the correction bolus determination in cases where the time duration, T
where h(τ) is the time derivative of h(τ). If D(T) is the time-dependent insulin bolus infusion rate function, the glucose drop at a give time relative to BG
To calculate at the current time T=T
To calculate a correction bolus amount, CB, to be given soon after T=T
The needed BG drop, ΔBG
Solving (6) for the integrals yields the equation:
wherein the quantity (h(T Referring again to Referring now to In the illustrated embodiment, the algorithm Following step At step In any case, if the control circuit In any case, if the time duration, T In the illustrated embodiment, the control circuit Those skilled in the art will recognize that the steps The present disclosure contemplates that the time duration, T
where IS Referring now to In the illustrated embodiment, the algorithm Step If at any time during the execution of the loop defined by steps From the Yes branch of step The present disclosure contemplates that either or both of the target glucose value, BGT, and the insulin sensitivity value, IS, may vary as a function of time during any one or more of the time intervals. In such a case, equation (6) may be modified to account for the time duration, T
where BGT(T where IS The present disclosure contemplates embodiments of the diabetes care system wherein the extended time period, e.g., one or more days, is not partitioned into a number of time intervals, but wherein continuous functions of the glucose target, BGT and the insulin sensitivity, IS, are defined for the entire extended time period. In such cases, the correction bolus equation may take the form:
In such embodiments, another modified version of the algorithm While the invention has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as illustrative and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. Patent Citations
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